Matthew Smith wrote:
After much searching in the "treasure house" of my shed, I have finally
found a transformer in the 9-10V range. Hooked it up to a spare
solenoid via bridge rectifier and filter cap an bingo - 398mV! Couldn't
have got closer if I'd tried. And yes, the solenoid operates fine.

Oops! Now I see that I forgot to re-calculate the impedance using the
root of the sum of the squares. Calculated current at 24V AC now
becomes 540mA; as it's working at close on 400mA, not a problem.

As I'm now running on 12V, I can now power the logic of the controller
through the guts of a mobile phone cig lead - removes need for a
separate supply. Guess that's the silver lining...

M